


Heroes Collide

by sepfish



Category: Harry Potter - J. K. Rowling, Percy Jackson and the Olympians - Rick Riordan, Septimus Heap - Angie Sage
Genre: Crossovers & Fandom Fusions, Dimension Travel, Gen, Other Additional Tags to Be Added
Language: English
Status: Completed
Published: 2018-09-24
Updated: 2019-01-03
Packaged: 2019-07-16 07:57:25
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 4
Words: 2,339
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16081820
Author URL: https://archiveofourown.org/users/sepfish/pseuds/sepfish
Summary: What happens when three heroes from three different books meet? Will they succeed in saving the world?





	1. And So It Begins

Septimus Heap woke to his House Mouse tapping on his nose. "Alright, alright," he said as he shooed it off and read the note in its hands, his eyes immediately drawn to the elegant purple script.

_Dear Septimus,_

__

_Please meet me in my study at noon exactly. There is something urgent I want to discuss with you._

__

_Marcia_

Septimus glanced at the clock. It was nine o'clock. He had only three hours until his 'appointment'. He sat on the edge of the bed and put his head in his hands, what Marcia wanted to talk to him about. Something told him it wasn't something good.

\------ 

"Alright. Percy Jackson, stop bringing the poodle. I don't know why you think it's okay, but it's not allowed!"

I was in theater, practicing for my school's production of Romeo and Juliet, which wasn't really a play but a , when my teacher yelled at me. I glanced at the teacher and saw Mrs. O'Leary chewing on the curtains.

Well. This was going to be fun.

"Hey, I don't control the, ahem, poodle," I said, "and I have no idea why she's here but I'll take it outside. Come on, Mrs. O'Leary!"

I heard the other kids snigger at the name, but I was more preoccupied by the fact that Mrs. O'Leary had came to my school. Which was definitely unusual. But whatever. Another day in the life of a demigod.

Mrs. O'Leary followed me out of the theater as I walked to the parking lot. Weirdly enough, I couldn't stop thinking that something was bound to go wrong at any minute.

\------ 

"Harry! Get up, we're going to Diagon Alley today."

Harry Potter sat up abruptly and almost smacked Ron, who had been the one to wake him, in the face. He rubbed his eyes and fumbled for his glasses. "What time is it, mate?"  
"It's three to eight. Mum was getting worried about you sleeping in, she wants to get there early. Here's your breakfast." said Ron, handing him a tray. He apparently didn't notice the orange juice spill over the cup slightly.

"Thanks," Harry said between bites.

A while later, Mrs. Weasley called everyone down. "This time, we'll be using the Floo network to get to Diagon Alley," she said. "Arthur couldn't get us a car."

"I liked the cars though," Fred complained.

"Shut your mouth, you know that you didn't like the cars," George said.

"And how do you know that?"

"Because you were complaining to me."

Mrs. Weasley sighed. "Harry, dear, you first. Fred, George, stop bickering."

Harry reached in the flowerpot, threw the powder in the flames, carefully folded his glasses and stuffed them in his pocket, and stepped forward. Suddenly, a sense of foreboding overcame him. He shook off the feeling and stepped in the flames. "Diagon Alley!" he shouted as the green whirled up around him.

**Notes for the Chapter:**

> This was originally written 3 years ago, and posted on Wattpad 2 years ago! Here's the shiny, new 2018 version of Heroes Collide.


	2. And So They Meet

Marcia leaned back in her chair. "Yesterday, Catchpole found a strange kind of swirling vortex. Do you happen know anything about this?"

Septimus shifted in his own chair. "Uh, no. Have you asked Marcellus?"

"Actually, I haven't heard from Marcellus lately," Marcia replied. "But that man could be doing some weird Alchemist business again and I need to get to the bottom of this. Now, could you do me a favor and look at it? I have never seen something like that before, and I would go and see it, but my shoes haven't delivered yet and I have no, ahem, practical ones left." Marcia did not mention that the reason for this was because she tripped in the vegetable patch.

Septimus smiled. "Of course," he said, getting up from his chair and closing the door gently behind him.

Marcia sighed. The other thing she hadn't mentioned to Septimus was that she was too scared to investigate it herself.

\------

"Alright, Mrs. O'Leary. What do you want with me?"

The hellhound barked at me, then sat down on her haunches.

"Huh?" Then it dawned on me. "Do you want me to ride you?"

Mrs. O'Leary barked her approval. Great, I thought. This day was becoming even more fun.

I tried my best to climb on Mrs. O'Leary's massive back without causing either of us bodily harm. Come to think of it, it really wasn't that different from climbing onto Blackjack. 

I mean, until she started running.

"Slow down!" I tried to shout, but it came out as an "Aaaaaaaaaaaagggghhhhhhhhh..."

Mrs. O'Leary took me out of the school, past the city, until we came to this empty meadow. Mrs. O'Leary sat down, and I promptly fell off and landed in some grass. Then she bounded away.

"I guess I'm stuck here," I grumbled, sitting up and rubbing my head. Checking my surroundings, I saw pretty much nothing but grass. And a boy.

\------

"This is definitely not Diagon Alley," Harry muttered to himself.

Somehow, he had found himself in a meadow... without any fireplace. He wasn't sure how that was possible, but he dealt with a lot of impossible things. 

Suddenly, he heard screaming to his left and saw two shapes coming his way—a giant dog, for some reason, and a boy. Harry just sat and stared until the boy came over to him. Or rather, fell off the dog and then came over to him.

"Uh, hello. I don't think I know you," he said with an American accent.

"I don't think I know you either," Harry said dryly.

The boy nodded, then stuck out his hand. "I'm Percy Jackson. What's your name?"

"My name's Harry. Harry Potter." The name Percy Jackson sounded suspiciously similar to him, but he didn't know why.

"Hey. Are you a wizard, by any chance?" Percy asked.

"What? Yes? Why?" Harry asked, taken aback.

"Oh, no reason," Percy said, apparently trying to hide a grin. "So. You have any idea why we're here?"


	3. And So Shenanigans Begin

Apparently one of the reasons why Marcia wanted him to see the vortex was because it took a long time to get there. By the time Septimus actually arrived at the vortex, he wasn't in the best of moods. An hour had already passed, his legs were dying, he was dying in the hot sun (he was questioning his choice to wear full-on Apprentice wear) and he was tired of squinting at the tiny map Marcia had hastily drawn on the back of her note.

He stood for a minute, just watching at the faint distortions in the air. He supposed it was interesting enough. From the side, if you looked at it, it would seem like nothing was there. But if you looked at it face-on, you would've just seen a shimmering cloud of white.

"Wow," Septimus said. Then he felt himself being drawn to it. His hands acted on their own, and even though his brain told him not to touch it, his hand stretched out... and...

silence. Septimus was gone.

The wind picked up suddenly, scattering dust and old leaves into the air.

\----- 

"The Greek gods are obviously superior," I frowned. Man, who did this guy think he was?

"I'm just saying—it's not great to value one over the other—they're pretty much the same, right?" Harry said. "It's not like are any major differences..."

"Dude, I will personally prove you wrong."

I was about to follow up on my words when a boy fell from the sky.

"Okay, we've already had one Apollo come from the sky. Is this another one?" I asked.

"Excuse me?"

"Long, long story. Maybe I'll tell it to you sometime."

"Okay. You know, instead of telling that story, maybe we could go over there to see if he's alright," Harry added.

I shrugged and followed him to where the boy had fallen. He looked nice enough—fair, crazy curly blond hair—but his fashion choices were strange, to say the least. He was wearing some odd kind of bright green tunic with a silver belt. On his feet were scruffy leather boots, tied with green laces of all things. 

"Hey, are you alright—" Harry began, when the guy sat up and almost knocked him over.

His eyes were bright green. I'm talking LED neon glowy evil crazy person green. But I supposed that that wasn't the weirdest thing I've seen.

"Who are you?" he asked, narrowing his eyes.

I looked him up and down and decided to trust him. "Hey, I'm Percy Jackson," I said. "And this is Harry Potter."

\----- 

The boy gave off the aura of a wizard. 

"Hey, I like your outfit," Harry said, then mentally berated himself. That was very smooth.

"Uh, thanks? It's an Apprentice outfit." 

"So," Percy butted in. "What's your name?"

The boy looked at the two of them and apparently decided not to answer. "What day is it?" he asked a little urgently.

"January 24, 2011?"

"August 21, 1994?"

The boy put his head in his hands. "Oh boy. Here we go again."

"Wait," Harry said. "You're joking, right? It's 1994."

Percy frowned. "To you, sure. It's 2011."

"You know, if you had a brain, which I'm sure you both don't, you would figure out that we're all from different time periods and different places. I'm not sure exactly how and why we are here, but it must be some kind of strange **Magyk**."

Percy and Harry looked miffed.

"Well, if you're so smart, what's your name then?" Percy frowned.

"Me? I'm Septimus Heap."

**Notes for the Chapter:**

> that roast tho  
> Septimus does not like being tossed in another Marcellus situation again.


	4. And So A Situation Arises

"So we're all from different times, huh," Percy said. "Why do the gods want us to meet, then?"  
"Any guess is as good as mine," Harry replied.  
"Uh, guys," Septimus said quietly, "I think someone's following us."  
The three of them immediately spun around. Nothing except grass.  
"I don't see anyone," Percy whispered.  
"They might as well be invisible," Septimus pointed out.  
"Here, I've got it," Harry said. " _Homenum Revelio!_ "  
Nothing happened.  
"What was that supposed to do?" demanded Percy.  
"It was supposed to reveal any human presences," said Harry. "And before you tell me it's rubbish, it does work!"  
"Hmm. Well, I guess it was nothing to worry about. We should be careful, though," Percy said.  
"Sorry, I guess I was just feeling a little jumpy," Septimus said, trying to ignore his Young Army instincts prickling at the back of his neck.  
\----  
They hadn't been walking for more than five minutes when a growl came from Percy's stomach.  
"Oh. I guess I'm hungry," Percy said. "You guys happen to have any food?"  
"No," Harry replied. "I can't conjure up any food either. It's not possible with this kind of magic."  
"That's pretty sad," Percy said.  
"It seems like we all have some kind of magical power. What can you do?" Harry asked.  
"Well, I can control water. Please don't call me Aquaman." Percy didn't mention anything else on the subject.  
"I see," Harry said. "Anybody else you know that can do stuff like you?"  
Percy seemed to perk up a little. "An—my girlfriend's got, like, a million IQ. And there are other people that I know that can... change into animals, and have healing powers, and there's one guy I know that can fly—"  
"Wait, your friend can fly too?" Harry asked. "That's amazing!"  
"Yeah. And... wait," Percy said, "where's Septimus?"  
Harry looked around. Septimus had apparently disappeared. "Where could he have gone? We're basically in a giant, flat meadow."  
"Is he invisible?" Percy said. "Hey, uh, Timius, you can come out now..."  
There was no reply.  
"Why did he go off?" Harry asked. "I'm pretty sure we were supposed to stay together."  
"Well then, we should look for him, shouldn't we?"  
Percy started jogging in the opposite direction. Harry followed a good distance behind, looking out for his green cloak and his fair hair. But he didn't see any sign of either.

\-----

Suddenly, he was alone. Percy had disappeared too.  
"Percy?" Harry called tentatively, but to an empty meadow. Panicking, he ran in a random direction and suddenly found himself in a familiar place, eerily illuminated by a sudden twilight.  
A hand pulled him down from behind a bush and Harry found himself face to face with Percy. "I think our friend Timius came out here. There are guards over there, by the way," he said. "Also, do you have any idea of where we are?"  
Harry peeked out and saw an all-too-familiar group of black-cloaked people standing around a group of houses. He sat back down to face Percy.  
"Actually, I do," Harry said. "We're in England. A road called Grimmauld Place."  
Percy looked confused. "Grim old place? Who names a road that?"  
"Grimmauld. My godfather lives—used to live here. And those people are wizards like me. Except they're bad. We call them Death Eaters."  
"Great, bad wizards. Are we going to fight them?"  
Harry looked shocked. "You're going to fight all of them?"  
"You don't want me to?" Percy said. "Should I just knock 'em out?"  
"Er, sure," Harry said, not sure of how to reply.  
Percy leapt up and ran towards the Death Eaters. A blade appeared out of nowhere, its blade glinting in the moonlight. It slashed and hacked and suddenly all of them were unconscious. Percy stood in the middle, unhurt. "Done," he announced.  
"That was—that was amazing," Harry said, a little taken back.  
"By the way, the building's missing number twelve," he said. "Is that on purpose? Or did the builder not know how to count?"  
Harry snorted at the thought. "No. Come here. I need you to... think about something. Repeat words in your mind."  
Percy raised an eyebrow. "May I ask why?"  
"Just— come here. And do it, please, unless we'll never get to the bottom of this. You need to think of... er... aha." He cleared his throat. "The headquarters of the Order of the Phoenix may be found at number twelve, Grimmauld Place, London." 

Harry hated doing it—he wasn't supposed to reveal the location of the Order—but as Dumbledore had said once, desperate times come for desperate measures.

And he was sure that these were desperate measures.

**Author's Note:**

> This was originally written 3 years ago and posted on Wattpad 2 years ago!


End file.
